BryE is sort of right.

Let me tell you first that FULL curing takes at least 3 months some people go as far as waiting 6 for reaching total hardness before assembling all together.

Yes you can absolutely apply clear coat to acrylic Duplicolor, for maximum durability I’d recommend the Duplicolor’s clear coat for aluminum (car) rims. It is especially formulated to be durable & withstand harsh chemicals BUT here’s the catch: it must be applied within 1-2 hrs from the last paint coat otherwise it just cures to a beautiful texture & I don’t believe you want that.

So go ahead get yourself at least 3 cans of CC & 1 of paint. Give it one thin paint coat all over serving as a touch up & “fresh” base for CC. If you are going to apply decals do it now.
Apply at least 3 thin layers of CC & let it dry. It is normal to see some cloudiness especially in humid environment don’t freak out. It dries clear.